[005/119] CIFS: fix oops in cifs_lookup during net boot

Greg KH
2009-12-07T00:36:47Z

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2.6.31-stable review patch. If anyone has any objections, please let us know.

------------------
From: Steve French <sfrench@us.ibm.com>

commit 8e6c0332d5032aef2d3bc8f41771f999112c8c66 upstream.

Fixes bugzilla.kernel.org bug number 14641

Lookup called during network boot (network root filesystem
for diskless workstation) has case where nd is null in
lookup. This patch fixes that in cifs_lookup.

(Shirish noted that 2.6.30 and 2.6.31 stable need the same check)

Signed-off-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Tested-by: Vladimir Stavrinov <vs@inist.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
fs/cifs/dir.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -648,7 +648,7 @@ cifs_lookup(struct inode *parent_dir_ino
* O_EXCL: optimize away the lookup, but don't hash the dentry. Let
* the VFS handle the create.
*/
- if (nd->flags & LOOKUP_EXCL) {
+ if (nd && (nd->flags & LOOKUP_EXCL)) {
d_instantiate(direntry, NULL);
return 0;
}
@@ -680,7 +680,7 @@ cifs_lookup(struct inode *parent_dir_ino
* reduction in network traffic in the other paths.
*/
if (pTcon->unix_ext) {
- if (!(nd->flags & (LOOKUP_PARENT | LOOKUP_DIRECTORY)) &&
+ if (nd && !(nd->flags & (LOOKUP_PARENT | LOOKUP_DIRECTORY)) &&
(nd->flags & LOOKUP_OPEN) && !pTcon->broken_posix_open &&
(nd->intent.open.flags & O_CREAT)) {
rc = cifs_posix_open(full_path, &newInode,